Gaseous electric discharge device



1933- M. PIRANI ET AL GASEOUS ELECTRIC DISCHARGE DEVICE Filed Feb. 10, 1932 WZa/vl'hz/ ATTORNEY Patented out. 10. 1933 1,930,150

GASEOUS ELECTRIC DISCHARGE DEVICE Marcello Pirani, Berlin-Wilmersdorf, and Martin Roger, Berlin, Germany, assig'nors to General Electric Company, a corporation of New York Application February 10, 1932, Serial No. 592,136, and in Germany February 14, 1931 3 Claims. (Cl. 176-124) The present invention relates to gaseous elecmanually each time the device is placed into optric discharge devices generally and more particeration since a lamp used for illuminating purularly the invention relates to such devices the poses is rarely in operation more than-six hours. gaseous filling of which is a mixture of gases, or a This reversal in polarity which occurs the second 5 gas and ametal vapor and which operate on direct time the lamp is placed into operation causes the current. I more electro-positive gaseous constituent to travel We have observed that the gaseous mixture in in the opposite direction from that in which it a gaseous electric discharge device operating on travelled in the first operating period which direct current has a tendency to separate into its causes first, a thorough mixing of the various con- 10 various gaseous constituents under the influence stituents of the gas mixture to overcome the sep- 5 I of the electric discharge in said device, the more arationthereof which took place in the first electro-positive constituent travelling toward the operating period and then a gradual separacathode. This phenomena is accompanied by a tion of the gas mixture as in the first operating change in the color of the light emitted by the period so that the time required for the separation 16 electric discharge device; that is, the color of the of the gases of the gas mixture to noticeably afemitted light changes from that of the gas mixfect the color of thelight emitted by said device ture at all parts of the container of said device to is approximately twice as long in the second opthat of the various gas constituents at different crating period than in the first. This phenomeparts of the device. This separation or de-mixna which occurs the second time the device is 20 ing of the gas mixture with the accompanying placed into operation takes place each time therechange in the color of the light emitted by said after that the polarity of the current applied to device is noticeable after a .comparatively short the electrodes of the device is reversed. period of operation, in the order of six hours, for The switch for reversing the polarity of the ex mple, and becomes more pronounced during currentapplied to the electrodes of the electric 25 eac operating period since the mixture of the discharge device consists of two electrically congases is only partly reestablished during the perducting ring members electrically insulated from iod that the device is not in operation. The each other and rigidly attached to each other object of this invention is to control the separation physically. Each of said ring parts is electrically of the gas mixture in a gaseous electric discharge connected permanently to one of the electrodes of 30 device operating on direct current to such extent the electric discharge device and is adapted to that there is no noticeable change in the color oi make electrical connection with one terminal of the light emitted by the gas mixture in said dea direct current source. The switch is so convice. Another object of the invention is to acstructed that when the rin p rts are turned complish this result by means external to said 180 from their original position each of said 35 device. A further object of the invention is to i g pa t is connected to the pp m nal '90 provide a simple switch connected into the circuit of said current source so that the pol of the of said device for reversing the polarity of the urr nt n aid d vic is v Wh n h current applied to the electrodes of said device. switch is turned from either of these twopo- Still further objects and advantages attaching to sitions the electric discharge device does not op- 40 the invention and to its use and operation will be erate since both rings are in electrical connection apparent to those skilled in the art from the 1501- with a sin l rm n l f h direct current lowing particular description and from the ap- SOIIICepended claims. e In the drawing accompanyingand forming part In accordance with this object the invention of this Specification an e h t 0f Our 111- 45 comprises the method f a d a, means for reversvention is shown schematically; in which,

ing the polarity of an electric discharge device Fig-1iSeschematicleplesehtation 0f a us operating on direct current at time i t 1 l electric discharge device and a circuit therefor than that time interval required for the separathe novel switch being h wn in n operating p0- tion of the gas mixture in said device to notice- SitiOn,

so ably efiect the light emitted by said gas mixture, Fig. 2 is a similar view of the device the switch This separation of the gas mixture takes place being Shown in an intermedlate 1 11 gradually and does not become noticeable until 3 is the Same as 1 the Switch being the device has been operating for approximately Shown in a different Operatlng position and in six' hours; therefore in the ordinary use of the which position the polarity of the current on said 55 lamp it is suflicient that the polarity be reversed device is reversed,

Fig. 4 is a similar view of the new and novel switch in another intermediate position, and

Fig. 5 is a front elevational view of the switch.

Like numbers denote like parts in all views of the device.

Referring to the drawing the electric discharge device 1 is filled with a mixture of gases or a mixture of gas and a vapor, such as a mixture of helium and argon, or a mixture of helium and mercury vapor. Said device 1 has at each end thereof an electrode 2 and 3 which may be of any conventional type. Said electrode 2 is connected by lead 7 to electrically conducting part 5 of the new and novel polarity reversing switch while electrode 3 is connected by lead 8, containing ballast resistance 9, to electrically conducting part 6 of said switch. Said parts 5 and 6 are electrically insulated from each other, but are rigidly attached to each other as shown in the drawing. Each of said parts 5 and 6 have laterally extending contact arms 10 and 11 respectively which are at an angle of approximately to each other and are adapted to make contact with contact segments 12, 13 as shown in Fig. 1. Said contact segments 12, 13 are connected by leads 14, 15 respectively to the terminals of a source of direct current.

In its first position, shown in Fig. 1, electrode 2 is connected to the negative terminal of the direct current source through lead 7, ring part 5,. contact arm 10, contact segment 12 and lead 14 while electrode 3 is connected to the positive terminal of the direct current source by lead 8, ring part 6, contact arm 11, contact segment 13 and lead 15. If the switch is turned by handle 4 through 90 both contact arms 10 and 11 make contact with only one contact segment 12, as

, shown in Fig. 2, the electric discharge device in this position of said switch is inoperative since both electrodes 2, 3 are then connected to the negative terminal of the direct current source. Another movement of handle 4 through 90 brings contact arm 10 into contact with contact segment 13 and contact arm 11 into contact segment 12, as shown in Fig. 3, so that the polarity of the current on said electrodes 2 and 3 is the reverse of that on said electrodes when the switch is in that position shown in Fig. 1. Another 90 turn of handle 4 makes the device 1 inoperative since both electrodes are connected to the positive terminal of the current source as shown in Fig. 4. A similar turn brings the switch to that position shown in Fig. 1. If desired a timing device such as a clock may be adapted to turn handle 4; through 180 to change the polarity on said device 1 at time intervals less than that time interval required for the separation of the gaseous mixture to affect the color of the light emitted by said device.

While we have shown and described and have pointed out various novel features of our invention it will be understood of course that various substitutions, modifications and changes in the form and details thereof and in its use and operation may be made by those skilled in the art without departure from the broad spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. The method of operating an electric discharge device comprising a container, a mixture of gases therein, electrodes sealed therein, said electrodes being connected to the terminals of a direct current source, which consists in changing the polarity of the current applied to said electrodes at time intervals less than that time interval required for the separation of the gas mixture to noticeably affect the color of the light emitted by the gas mixture in said device.

2. In combination, an electric discharge device comprising a container, a mixture of gases therein, electrodes sealed therein, said electrodes being connected to the termina s of a direct current source, and a switch interposed between said source and said device for changing the polarity of the current applied to said electrodes whereby separation of the gas mixture is avoided.

3. In combination, an electric discharge device comprising a container, a mixture of gases therein, electrodes sealed therein, said electrodes being connected to the terminals of a direct current source, and a switch interposed between said source and said device for changing the polarity of'the current applied to said electrodes at time intervals less than that time interval required for the separation of the gas mixture to noticeably afiect the color of the light emitted by the gas mixture in saiddevice.

MARCELLO PIRANI. MARTIN REGER. 

